Electrical energy is applied to the brain to treat a variety of clinical conditions such as movement disorders or chronic pain. One method of delivering electrical energy to the brain involves inserting an electrical stimulation lead through a burr hole formed in the skull and then positioning the lead in a precise location adjacent a target area of the brain to be stimulated such that stimulation of the target area causes a desired clinical effect. For example, one desired clinical effect may be cessation of tremor from a movement disorder such as Parkinson's Disease. A variety of other clinical conditions may also be treated with deep brain stimulation, such as essential tremor, tremor from multiple sclerosis or brain injury, or dystonia or other movement disorders. The electrical stimulation lead implanted in the brain is connected to an electrical signal generator implanted at a separate site in the body, such as in the upper chest.
Electrical stimulation leads implanted in the brain require precise placement because of the relatively small size of the target area in the brain and because of the relatively close proximity of other non-targeted anatomic regions in the brain. One method of achieving precise placement is through a stereotactic surgical procedure that uses radiographic or fluoroscopic images of the brain to guide the surgeon to the target area. This may require placement of a three-dimensional frame to the head such that horizontal and vertical coordinates of the target area may be compared to radiographic images and precisely located. Other stereotactic methods may include a frameless procedure. Once the precise location of an electrical stimulation lead in the brain is achieved it is important that the lead remain in its precise position to avoid injury to the brain, reduced effectiveness, or other undesirable effects. An electrical stimulation lead may be particularly prone to being dislodged when a stereotactic frame is disassembled and removed from the head, for example, after insertion of the lead. When the frame is being disassembled and removed from around the insertion site, a doctor, nurse, or other clinician must typically attempt to manually secure the exposed end of the electrical stimulation lead in an attempt to maintain the precise positioning of the lead in the brain. This is difficult, if not impossible, to accomplish in practice.